Twist-drill gauge



n. w m m A. Vl. AMSDEN.- Twlsr DRILL GAUGE. FILED um@ 2. |922.

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Patented Dec. l, l922.

narran stares f tisana refinar eerie ALBERT WASHINGTON AMSDEN, OF ATHOL,MASSACHUSETTS, ASSIGNOR T0-THE L. S.

STABRETT COMPANY, OF ATHOL, MASSACHUSETTS, A CORPORATION' OF MASSA-CHUSETTS.

TWIST-DRILL GAUGE.

Application led March 2, 1922. Serial No. 540,595.

To all whom t may concern Be it known that I, ALBERT W. AMsDnN,

a citizenv ot the United States, residing at' ilithol, county ot'lVorcester, Commonwealth ot' Massachusetts, have invented certain newand useful improvements in rTwist-Drill Gauges, of which the followingis a speci- .tica-tion.

This invention relates to gauges, and particularly to a gauge forgaugingdrill points. ln the manufacture et drills it is essential thatthe drill be properly ground -at the point in order to insure maximumrcutting clliciency and to avoid splitting, It the cutting edges are notuniformly ground, that is iit lboth cutting edges are not oi the saineangle and length with relation to the drill axis, the drill will `notcut to size. For the majority et operations an angle ot 590 is generallyaccepted as correct.

To the end therefore ot providing a simple and inexpensive tool for accuately gauging drill points, l have devised my present invention.

iiccording to my invention, the drill to be gauged is laid against ablade with its axis parallel to the straight edge thereof and with itscutting edge disposed against a graduated gauge piece mounted on saidstraight edge at an angle oi' ff thereto, this being the angle generallyaccepted as correct for the majority of work. The point on 'thegraduated gauging edge at which the center of the drill comes is thennoted, whereupon the drill is turned to present its other cutting edgeto the gauge, and il the center of grinding comes on the gauging edge atthe same point at which it came when the first cutting edge was gauged,the operative knows that the drill is accurately ground. y Y Theconstruction and operation of my gauge is described and illustrated inthe accompanying speciication and drawings, and the characteristicfeatures ot' novelty are particularly pointed out in the appendedclaims. Throughout the. specification and drawings lilre referencecharacters are correspondingly applied. and in the drawings:

Fig. l is an elevation of a gauge in ac coi-dance with my invention andindicating the manner of use thereof in gauging a drill point,4 y

Fig. Q is an enlarged Jiragineifitary detail, partly in section, andFig. 3 is a ver` tical section through the parts shownl in Fig. 2.

I have indica-ted' at l a graduated blade such as is ordinarilyT used inthe familiar square. Adjustable along said blade is a ll-shaped head ora stirrup 2. The adjustment of said head is held by a set screw 3 whichengages and carries a clamp 4 disposed across the closedv bottoinpof thestirrup' into engagement with the bottom edge of the blade l. j

Fixed edgewise, as by welding in theopen end ot' the stirrup yto restflatlyon thev upper edge of the' blade l is a gauge piece 6. The gaugepiece 6 is generally of right triangle 'form and its hypotenuse 7 isdisposed at an angle of 590, preferably, to the blade inch, as indicatedat 8, to constitute a gang`- ing edge.

In use, the blade l is ordinarily held in the left hand with thegraduations 8 'facing the user and the drill D to be gauged is held inthe right hand with one of its spiral edgesy laid against the adjacentedge of the blade. The drill is thus positioned with its axis parallelto the blade l and with one of its cutting edges C disposed against thegraduated gauging edge 7 of the gauge piece 6. The operative notes wherethe center of the drill comes with respect to the graduations 9 and thenrotates the drill to present the other cutting edge to the gauging edge6. If the center of the grinding comes upon the graduations at the samepoint as did` the iirst-gauged cutting edge, the operative will knowthat the drill is accurately ground.

ln addition to its use as a drill gauge, the slidable head 2 adapts thegauge for us as a hook rule or a depth gauge or even a square.

Various other modifications in the construction and use of my device mayobviously be ina-de without departing from the spirit of my invention itwithin the limits of the appended claims,

l/Vhat l therefore claim and desire to secure by LettersPatent is:

l.. i drill gauge comprising a blade against which a drill is adapted tobe laid with its axis parallel thereto, a head provided with anopen-ended slot and adjust# able longitudinally along said blade, meansfor holding the adjustment of said head, a gauge piece mounted in theopen end ot' said slot and secured to ysaid head, said gauge pieceseated against the adjacent edge ot the blade to lie in the sanne planetherewith and having a graduated gauging edge disposed at an angle ofapproximately 590 to said blade and against which the cutting edges otthe drill are adapted to be successivelylaid upon relative rotation ofthe drill and gauge piece to indicate the angular relation of saidcutting edges to the drill axis.

2. A drill gauge comprising a blade against which a drill is adapted tobe laid With itis axis parallel thereto, a head provided With anopen-ended slot and adjust* able longitudinally along said blade, meansfor holding the adjustment of said head, a substantially righttriangular gauge piece mounted in the open end of said slot and securedto said head, `said gauge piece having its base seated against theadjacent edge of the blade to lie in the same plane therewith and Withits hypotenuse graduated and disposed at. an angle oit approximately 59Oto said blade and against which the cutting edges of the drill areadapted to be successively laid upon relative rotation of the drill andgauge piece to indicate the angular relation of said cutting edges tothe drill axis.

3. A gauge compris-ing a blade, a U- shaped head straddling said bladeand slidable therealong, a clamp interposed between the closed end ofsaid head and tho adjacent edge of the blade, and movable against .saidblade edge to hold the adjustment of said head, and a gauge piecemounted in the open end of said head and secured to said head, saidgauge piece seated against the adjacent edge ot' the blade to lie in thesame plane therewith and having a graduated gauging edge disposed at anangle to said blade.

ln testimony whereof I alii; my signature in presence of tivo Witnesses.

ALBERT WASHiNGTON AMSDEN. W'itnesses lvVILLmixr E. CROMER, ALTER L.MAYHEW.

